import { useRef } from 'react'
function App () {
  let inputref = useRef(null)
  const showDown = () => {
    console.log(inputref.current);
    inputref.current.focus()
  }
  return (
    <div className="App">
      <input type="text" ref={inputref} />
      <button onClick={showDown}>获取DOM</button>
    </div>
  )
}

export default App
